Drilling apparatus



March 4, 1941. R B BRYANT v 2,233,692

DRILLING APPARATUS Filed April 20, 1959 2 Sheets-Sheet 1 me/whom 2 Sheets-Sheet 2 R. B. BRYANT DRILLING APPARATUS Filed April 20, 1939 March 4, 1941.

Patented Mgr. 4, 1941 n UNITED STATES panama APPARATUS y my B. Bryant, panas, Tex.; Frank Leone Bryant executrix of said Roy B. Bryant, deceased Application April'20, 1939, Serial No. 268,876

11 Claims.

This invention relates to new and useful improvements in drilling apparatus. i

In the drilling of wells, it is the general practice to circulate a drilling fluid, such as mud, downwardly through the drill stem or pipe and then upwardly through the well casing for the purpose of lubricating the rotating drill bit and also to carry the cuttings to the surface. Since thediameter of the casing is greater than the diameter of the drill stem, the velocity of the circulating fluid drops when it flows from said stem to said casing, with the result that a relatively high pump pressure must be maintained on the fluid entering the drill stem in order that suiilcient pressure for circulation is had when the iluid flows into and enters the casing.

It has been found that by circulating the drilllng lin a reverse direction, thatfis, flowing the same downwardly through the casing and upwardly through the drill steiny or pipe, much less pump -pressure is necessary to maintain sulcient velocity for proper circulation. In employing reverse circulation, the uid flows downwardly through the casing to the bottom of the hole and then upwardly through ports in the drill bit into the stem. With this method, the iluid is not directed againstthe cutting edges of the bit, as is the case when conventional circulation is employed, and this detracts from the use of reverse circulation because the bit is not properly lubricated, particularly when the bit is rotating in soft or sticky formations. Further, in using reverse circulation, the drill stem must be packed off from the Well casing at the upper end thereof and the present pack-off devices, now in general use, are rather complicated .and expensive, which also discourages the use of a circulation method other than the conventional.

It is one object of the invention to provide an improved apparatus whereby reverse circulation ofthe drilling fluid may beemployed during the drilling operation Without the disadvantages outlined above, and also without the other disadvantages which have heretofore been encountered by the use of such method of circulation.

An important object of the invention is to provide an improved apparatus which is arranged so that the drilling fluid may be circulated through the well in a direction reverse to the conventional method, and which has means for positively directing the fluid against the cutting edges of the drill bit to properly lubricate and clean said bit and alsoto assure carrying the removed cuttings to the surface. |5 Another object of the invention is to provide (Cl. Z55-1) an apparatus for practicing the reverse circulation of drilling fluid through the well bore which includes an improved means of packing oil between the drill stem and casing, said means being simple in construction .and being substi- 5 tuted for the usual complicated swivel and packof! heads and devices now in general use.

A funther object of the invention is to provide an improvedapparatus, of the character described, having a sub or collar connected above the drill bit for diverting the drilling uid from the well casing downwardly through the bit and thence upwardly around the bit and to the drill stem, whereby the action of the uid on the bit is substantially the same. as when the conven- 15 tional method of circulating the drilling fluid is employed.

Still another object of the invention is to provide an improved apparatus for permitting reverse circulation of drilling fluid which includes a flexible sealing member arranged to seal olf` between the well bore and drill stem above the drill bit, whereby the fluid flowing downwardly through the casing cannot pass to the outside of the bit; said collar being adapted to be distorted and held in sealing position by the circulating drilling uid and also being removably mounted so as to be readily replaceable when worn or for any other reason.

A construction designed to carry out the invention will be hereinafter described, together With other features of the invention,

, The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, in

' which van example of the invention is shown,

andwherein:

Figure l is a view, partly in section and partly in elevation, of an apparatus, constructed in accordance with the invention and showing the 4o same within a well bore,

Figure 2 is an enlarged, horizontal,.crosssec tional view, taken on the line 2-2 of Figure 1,

Figure 3 is an enlarged, horizontal, cross-sectional view, taken on the line 3-3 of Figure 1,

Figure 4 is an enlarged, transverse, vertical, sectional view, taken on the line 4 4 of Figure 1,

Figure 5 is an enlarged, transverse, vertical, sectional view, :taken on the line 5 5 of Figure 1,

Figure 6 is a view similar to Figure 5, and taken 50 at substantially'a right angle thereto, and

Figure 7 is a horizontal, cross-sectional view, taken on the line 1-1 of Figure 5.

In the drawings, the numeral I0 designates a well bore through which the well casing Il ex- 55 tends. The upper end of the well casing is externally screw-threaded to receive a casing head I2 which is provided with a lateral port I3. A

suitable inlet pipe I4 is threaded into the port I3, whereby a drilling uid may be conducted into the bore of the well casing.` The head I2 is provided with an external, annular iiange I5 at its upper end and this ange is bolted to the flange I6 of a suitable blowout preventer I1. The blowout preventer I1 may be of any suitable construction and, as shown, includes a body having an axial bore I8 extending therethrough. A pair of laterally directed openings or passages I9 are formed within the body of the blowout preventer, as is clearly shown in Figure 3, and these openings intersect the bore I8. A U-shaped member 20 has its arms slidable within the passages I9 and when said member is moved inwardl'y the arms 2| of said member overlie a portion of the bore. When the member 28 is removed from the port, the bore I8 is lunrestricted to permit the passage of tools, or other elements therethrough.

An elongate cylinder 22, which is open alt its ends, has its upper end screw-threaded into the lower end of the bore I8 of the blowout preventer I1, whereby said cylinder is suspended axially within the well casing I I. The lower end of the cylinder is flared outwardly, as shown at 23, whereby tools` which are pulled upwardly through the cylinder are guided into the bore rthereof by the ared portion. A plurality of ports or openings 24 are formed in this iiared portion, whereby an unrestricted flow of fluid, which is passing downwardly through the well casing Il, `may ilow through said ports.

The tubular drill pipe or stem 25 extends axially through the well casing and through the well bore and has its upper end connected to the lower end of a tubular mandrel 26, as is shown in Figure 4. The upper end of the mandrel 26 is coupled to the lower end of an anp guiar drive member or kelly 21, whereby said mandrel couples the kelly to the lu'pper endv of the drill stem. A suitable annular packing sleeve 28 is mounted on` the mandrel and is constructed of an elastic material, such as rubber, duprene, or the like. The outer diameter of the packing sleeve 28 is substantially equal to the diameter of the bore of the cylinder 22, whereby the outer surface of the packing sleeve frictionally engages the wall 'of said bore. The packing sleeve is arranged to move downwardly through the cylinder 22, as the drilling operation progresses and,

manifestly, said sleeve will serve to pack ofi,

around the drill stem, whereby iluid within the lower end of the cylinder and within the casing cannot pass upwardly around the drill stem. The sleeve will, of course, serve to hold the pressure and prevent it from leaking upwardly past the drill stem and kelly.

The lower end o1' fthe drill stem 25 is connected by a suitable coupling collar 23 with the upper end of a tubular mandrel or sub 38. As is clearly shown in Figures 5 and 6, the sub is provided with an axial bore 3| which extends from its upper end to a point just above its lower end. A plurality of radial ports or openings 32 extend from the lower end of the bore 3l to the ourter surface of the sub, whereby iiuid may enter the lower: end of the bore. v

An external, annular ilange 33, which is preferably made' integral with the sub 'or mandrel 38, is formed thereon and is located intermediate the ends thereof. The underside,I of the assaesa flange 33 is bevelled or inclined, as shown at 34. An annular. elastic packing sleeve 35 surrounds the sub or mandrel and has its lower end tapered inwardly so as to rotatably engage around the sub immediately below the shoulder 33. A

retaining thimble 38 surrounds the sub and has its upper end overlying the lower end of the packing sleeve 35, whereby said packing sleeve is rotatably conned on the sub between said thimble and the shoulder 33. The thimble is removably fastened to fthe .sub by means of tap screws 31 which are threaded into the exterior surface of said sub. The upper end of the packing sleeve 35 is bevelled or inclined inwardly as shown at 35'. By observing Figures 5 and 6, it will Abe seen that' the upper portion of the bore of the sleeve 35 is of a larger diameter than the external diameter of the sub or mandrel 38.v

whereby an annular space 38 is'formed between the sleeve and said hub.

The lower end of the sub 38 is .threaded onto the usual upwardly extending pin 39 oi' an ordinary drill bit 48. As is clearly shown in Figure 1, the bit is provided with an axial bore 4I, which has its lower end communicating with the usual inclined ports or uid passages 42. The upper end of the pin' or the drill bit 48 is spaced from the underside of the transverse partition 38', which partition extends transversely across the interior of the sub or mandrel and serves to close the lower end of the bore 3 I For establishing communication between the well bore or casing above the packing sleeve 35 and the axial bore 4I of the drill. bit, a plurality of vertical passages 43 are yformed in the sub r mandrel 38 (Figure 6). upper end inclined outwardly and communicates with the annular space 38 which is formed between the mandrel and the packing sleeve 35. The lower end of the passage extends downwardly through the partition 38', whereby fluid from the annular space 38 may flow downwardly and to the axial bore II of `the drill bit.

In the operation of the device, the parts are assembled as shown in Figure 1, with the lower .Each passage has` is l bore I8. The upper packer 28 is located within the cylinder 22 and it is noted that said packer remains within said cylinder at all times. The kelly joint 21 has its upper end extending through the usual rotary table (not shown), whereby said'joint is rotated. A's said joint rotates, the packing sleeve 28 is rotated within the cylinder 22 and the drill pipe 25 is also rotated to `impart a rotation to the drill blt 48. It is pointed out that'the particular mounting ofthe lower packing sleeve 35 is such that said sleeve lcontacts the wall of the bore I8 trictionally and the mandrel or sub 38 is rotatable therein. In other words, the sleeve 35 is merely coniined on the sub and is capable of being held stationary, while said sub is rotating therein.

The drilling fluidis introduced into the upper end of the well casing through the pipe I 3 and passes downwardly throughfsaid casing. Thisdrilling fluid ows through -the ports 24 in the lower flared end of the cylinder 22 and their downwardly into the bore I8 above the lower 'l I fasieg. iiew to the bore il of the armpit u. From tnebore 4I', the drilling fluid will pass outwardly through the inclined port I2 and will be directed against the cutting edges of the bit to properly lubricate and wash said blades. The drilling fluid will then pass upwardly through the well bore and will flow through the radial ports 82 which are provided in the lower end of the sub. The drilling fluid'cannot pass upwardly through the bore through the kelly joint 21 to the swivel (not against .the cutting edges of the drill'bit blades stem is lifted to the surface so that the packer and acts to keep said edges clean and free from accumulations. Also, by directing the drilling fluid Aagainst the blades in this manner at the bottom of the hole, it is assured that the cuttings which are removed by the rotating bit will be carried to the surface through the drill stem.

As the drilling progresses, the upper packing sleeve 28 moves downwardly through the elongate cylinder 22 so as to hold the pressure and prevent'its escape upwardly around the drill stem and kelly joint. -At the same time, the lower packing sleeve moves downwardly through the well bore I0 and, since this lower sleeve does not rotate, it is not subjected to a great deal of wear.

After sufficient hole has been drilled to cause the packer 28 to have moved downwardly to the lower end of the cylinder 22, it is necessary to insert another section of the drill pipe 25 before drillingA is continued. In such event, the drill 28 is removed from the cylinder and also from the bore I8 of the blowout preventer I1 above said cylinder. The upper end of the drill pipe 25 is then ldisconnected from the lower end of the mandrel 26 andsanother section of drill pipe connected between these two parts. After this is done, the drill stem is again lowered so as to lower the packing sleeve 28 into its cylinder 22. The drilling operation is then continued.

lIn the event that an excessive pressure should occur below the packing sleeve 28, said pressure would tend to force the same upwardly through its cylinder 22, with-the result that the drill stem might be blown from the well. In order to prevent such blowout, the preventer I1 has been provided. Manifestiy, with the U-shaped member or yoke 20 retracted from its passages I 9, the bore I8 of the blowout preventer is unrestricted and the packing sleeve 28 may readily pass therethrough. However, if an excessive pressure occurs and the kelly joint |begins to move upwardly, the operator need only move the member or yoke 2Il,inwardly of the passages I9. Such movement will cause the yoke arms 2I to intersect the bore I8 of the blowout preventer and, as is clearly shown in Figure 3, such position of the arms will restrict the area of said bore. Therefore, as the packing sleeve 28 is movedupwardly by the excessive pressure, it will finally strike the 'arms of blowout preventer forms no part of the present invention and, so'iong as some -means i 'or preventing excessive pressure lifting the drill stem from'the well is provided, the purpose of the invention will be accomplished.

' The foregoing description of the invention is explanatory thereof and various ychanges In the size, shape and materials, as well as in the details of the illustrated construction, may be made, withinv the scope of the appended claims, without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is:

' l. A drilling apparatus' including, a rotatable tubulardrill stem, a drill bit havingfluid passages therein secured to the lower end of said stem, whereby when the stem is rotated the bit performs the cutting operation, means for circulating a drilling uid downwardly through the well borev outside of the stem, means for conducting the fluid from the bore to the fluid passages of the bit so asv to direct said fluid into contact with the cutting blades thereof, and means for conducting .the iluid'upwardly through the drill stem to complete the circulation cycle.

2. A drilling apparatus including, a. rotatable tubular drill stem', a drill bit having fluid passages therein secured to the lower end of said stem, whereby when the stem is rotated the bit performs the cutting operation, and .a connecting mandrel interposedl between the bit and stem and having an axial bore which`has its upper end communicating with the bore of the drill stem and. its lower end communicating with the well borey immediately above the bit, said mandrel having vertical passages therein forI conducting fluid from above the mandrel downwardly to the passages of the bit, whereby drilling fluid flowing downwardly through the well bore is conducted through the vertical passages of said mandrel to the bit and flows therethrough after which? said fluid may pass upwardly through the bore of the mandrel and stem.

3. A drilling apparatus including, a rotatable tubular drill stem, a drill bit having fluid passages therein secured to the lower end of said st'em, whereby when the stem is rotated the bit performs the cutting operation, and a connecting member interposed between the stem and drill bit and having a fluid inlet in its upper end which communicates with the fluid passages of the bit and also having an outlet in its lower end which communicates with the drill stem, and means for sealing oiI the annular space between the drill stem and wellbore, said sealing means being disposed between the inlet and outlet of the connecting member, whereby drilling fluid owing downwardly through the -well bore is conducted through the inlet and bit and then upwardly through the outlet and drill stem.

4. A drilling apparatus including, a rotatable tubularl drill stem, a drill bit having uid ypassages therein secured to the'lower end of saidstem, whereby when the stem is rotated the bit performs the cutting operation, means surrounding the upper portion of the drill stem for packing off the annular space between said'stem and the Well bore, means for circulating a drilling fluid downwardly through the Well bore outside of the stem, means for conducting the fluid from the bore to the fluid passages of the bit so as to direct said fluid into contact with the cutting blades thereof, and means for conducting the fluid upwardly through the drill stem to complete the circulation cycle.l

` tubmar drm stem, s drm bit having num passages therein secured to the lower end' oi' said stem, ,whereby when the stem is rotated the bit performs the cutting operation, a connecting member interposed between the stem and drill bit and having a iluid inlet in its upper end which communicates with the duid passages of the bit and also having an outlet in its lower end which communicates with the drill 'As/tcm,-

means for sealing of! theV annular space between the drill stem and well bore, said sealing means being disposed between the inlet and outlet oi' the connecting member, means secured to the upper end of the drill stem for packing of! between said stem and the bore, and means for circulating a drilling fluid downwardly through the bore, whereby said fluid ilows downwardly through the inlet of the connecting member and through the bit and then upwardly through the outlet and the drill stem.

6. Aldrilllng apparatus including, a rotatable tubular drill stem, a drill bit having uid passages therein secured to the lower end of said stem, whereby when the stem is rotated the bit perform the cutting operation, a connecting mandrel interposed between the bit and stem and having an axial bore which has its upper end communicating with the bore of the drill stem and its lower end communicating with the well bore immediately above the bit, said mandrel having vertical passages therein for conducting fluid from above the mandrel downwardly to the passages of the bit, and an elastic packing sleeve surrounding the mandrel for packing oli the annular space between the mandrel and well bore, whereby drilling uid owing downwardly through the well bore is conducted to the bit and flows therethrough after which said fluid may pass upwardly through the mandrel and stem.

7. A drilling apparatus including, a rotatable tubular drill stem, a drill bit having fluid passages therein secured to the lower end of said stem, whereby when the stem is rotated the blt performs the cutting' operation, a connecting memberl interposed between the stem and drill bit and having a uid inlet in its upper end which communicates with the fluid passages of the bit and also having an. outlet in itslower end which communicates with the drill stem, and an annular elastic packing element actuated by fluid pressure for sealing oil the annular space between the drill stem and well bore, said sealing element being disposed between thednlet and outlet of the connecting member, whereby drilling uid iiowing downwardly through the,y v,well bore is conducted through lthe inlet and bit and then upwardly through the outlet and drill stem. l,

8. A drilling apparatus including. a 'rotatable tubular drill stem, a drill bit having fluid passages therein secured to the lower end of said stem, wherebyv when vthe stem is rotated lthe bit performs the cutting opera/tion, a connecting member interposed vbetween the stem and drill bit and having a iluid inlet in its upper end which communicates with the fluid passages of the bit and also having an outlet in its lower end whichcommunicates with the drill stem, and an annular elastic packing element actuated by uid pressure for sealing off the annular space between the drill stem and well bore, said sealing element being disposed between the inlet"and outlet of the connecting member. means secured to the upperA end oi the drill stem for packing o! between said stem and the bore, and imeans for circulating a drilling nuid downwardly through the bore, whereby said iluid flows downwardly through the inlet of the lconnecting member 'and through the bit and then upwardly `through the outlet and the 'drill stem.

9. A drilling apparatus including, a rotatable tubular drill stem, a drill bit having iluid passages therein secured to the lower end of said stem, whereby when the stem is rotated the bit performs vthe cutting operation. a connecting member interposed between the stem and drill bit and having a iluld inlet in its upper endk which communicates with the uidpassages'. of the bit and also having an outlet in its lower end which communicates with the drill stem. means for sealing o3 the annular space between the drill stem and well bore, said sealing means being disposed 'between the inlet and outlet of the connecting member, an elongate cylinder surrounding the upper portion of the drill stem. a4

packing element mounted on the stem and hav ing sealing engagement-with the cylinder wall to pack oil around the stem, and vmeans for circulating a drilling iluid downwardly. throughthe bo're, whereby said iiuid flows downwardly kthrough the inlet of the connecting member and through the bit and then upwardly through the outlet and the drill stem.

tubular drill stem, a drill bit having fluid passages-therein secured to the lower end of said stem, whereby when the stem is rotated the bit performs the cutting operation, a connecting member interposed between the stem and drill bit andfhaving a uid inlet in its upper end which communicates with the iluid passages of the bit and also having an `outlet in its lower end which communicates with the drill stem, means for sealing of! the annular space between the drill stem and well bore, said sealing means being disposed between the inlet and outlet of the connecting member, an elongate cylindeg surrounding the upper portion oi' the drill stem. a packing element mounted on the stem and having sealing engagement with the cylinder wall to pack oil around the stem. means forcirculating a' drilling iluid downwardly through the bore, whereby said fluid flows downwardly through the inlet of the connecting member and through the bit and then upwardly through the outlet and the drill stem, anda blowout preventer at the surface of the well bore arranged to be actuated to prevent the drill stem from being blownx from the well by an excessive pressure.

l1. A drilling apparatus including; `a rotatable tubular .drill stem, a drill bijt having fluid passages therein secured to the lower end of said stem, whereby when the stem is'rotated the bit performs the cutting operation, an elongate cylinder surrounding the upper portion of the drill stem. an elastic packing member surrounding the stem and having a sealing engagement with the cylinder wall to pack oli around the stem, means for circulating a drilling uid downwardly through thewell bore outside of the Istem and cylinder, means for conducting the iluid from the bore to the vuicl passages of the bit so as to direct said uid into contact lwith the cutting blades thereof, and means for conducting the fluid upwardly through the drill stem to complete 'the circulation cycle.

ROY B. BRYANT.k

. 30 10. A drilling apparatus including, a rotatable f 

